This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Persistent diarrhea is the predominant clinical sign of gastrointestinal (GI) disease and is one of the leading causes of morbidity in captive nonhuman primates (NHPs). It has been estimated that in approximately 50% of cases, the etiology of diarrhea is undetermined. The purpose of this resource-related research project proposal is to examine the role of selected, recently recognized and/or under-diagnosed causes of GI disease in the TNPRC rhesus breeding colonies and to develop intervention strategies that can be applied toward the long-term goal of reducing morbidity in rhesus macaques at the TNPRC. To begin to achieve these goals, the specific aims are;1) Determine the prevalence and incidence of selected, recently recognized and/or under-diagnosed infectious causes of GI disease in rhesus macaques at the TNPRC to evaluate their association and risk with GI disease. The agents will include bacteria (Campylobacter), viruses (calicivirus and rotavirus), and the enteric parasitic microsporidia. 2) Evaluate the association between dietary gluten sensitivity in relation to GI disease, immune status, and demographic factors. These infectious agents (species or genotypes) and dietary sensitivity are currently not included on the routine diagnostic protocols provided by the core service laboratories at the TNPRC but have been recently recognized as probable contributors to overall morbidity attributable to GI disease in NHPs at the TNPRC. 3) Develop intervention strategies for reducing the incidence of GI disease. Prevalence, clinical, and demographic data generated in aims 1 and 2 will be evaluated by statistical analyses to measure risk factors associated with GI disease. Prevalence data will be based on the detection of the selected agents suspected of contributing to GI disease. The clinical data will primarily include occurrence of diarrhea, weight loss, and fever. Demographic information will include age, gender, body weight, housing conditions (location, field cage size, population size, female:male ratio), seasonality, and medical history (previous clinical admissions and cause, pregnancy outcomes). The results will be used to generate intervention strategies or algorithms that subsequently can be applied in future studies to test proof of concept. Predicted strategies include the implementation of new protocols in the TNPRC diagnostic core laboratories, selectivity in treatment, modification of sanitation procedures, relocation or limited quarantine of affected animals, dietary changes, and changes in animal husbandry practices. The outcome of this study is expected to improve the resource value of the NHPs that are used as models to study human disease.